Christmas is looming, and investigator Catherine Berlin is out of a job. Broke, and with a drug habit that's only just under control, she quickly agrees when an old friend offers her work. It's a simple investigation with a generous fee, looking into the dealings of a small-time entrepreneur. The only catch? It's in Russia.

But when Berlin arrives in Moscow, things are not so straightforward. Shadowy figures stalk her through the frozen streets. She's kicked out of her hotel, her all-important medication confiscated by police. Strung out and alone, Berlin turns to her interpreter, an eccentric Brit named Charlie. But Charlie's past is as murky as Berlin's own, and when the subject of the investigation disappears, Berlin realises Charlie may be part of the web. The only way out is to hunt down the truth, even if it kills her.